Silver Nanoparticles and Graphitic Carbon Through Thermal Decomposition of a Silver/Acetylenedicarboxylic Salt

Abstract

Spherically shaped silver nanoparticles embedded in a carbon matrix were synthesized by thermal decomposition of a Ag(I)/acetylenedicarboxylic acid salt. The silver nanoparticles, which are formed either by pyrolysis at 300°C in an autoclave or thermolysis in xylene suspension at reflux temperature, are acting catalytically for the formation of graphite layers. Both reactions proceed through in situ reduction of the silver cations and polymerization of the central acetylene triple bonds and the exact temperature of the reaction can be monitored through DTA analysis. Interestingly, the thermal decomposition of this silver salt in xylene partly leads to a minor fraction of quasicrystalline silver, as established by HR-TEM analysis. The graphitic layers covering the silver nanoparticles are clearly seen in HR-TEM images and, furthermore, established by the presence of sp 2 carbon at the Raman spectrum of both samples.

Insights of the formation mechanism of nanostructured titanium oxide polymorphs from different macromolecular metal-complex precursors

“…Here we will focus on the formation of carbon species in order to elucidate the nucleation of TiO2 particles since, as based on the literature, it is believed that a graphitic layer plays a crucial role on the nanoparticle formation. The precursors (I), (II), (III), (IV), (V), and (VI) were annealed at 400 C and their Raman spectra are shown in Figure 1, where the typical D and G graphite bands [18,41,42,43,44] are observed. These bands are not clearly defined in some cases, as observed for the macromolecular precursor (III) and (V).…”

Biosynthesis of Ag/MWf-CNT Nanocomposites Using Aspergillus fumigatus as the CO Oxidation Catalyst

“…As it can be seen, the absorption spectrum corresponding to carbon nanotubes shows a peak at 252 nm, which is the characteristic peak of functionalized carbon nanotubes (C=C bond) [25] . The slight shifts are observed in both characteristic peaks of CNT and AgNPs toward lower wavelengths after reduction of Ag ions (Figure 1), this is due to the coupling of the surface plasmon electrons with the sp 2 carbon atoms of the graphitic layers [26] . Also, by increasing the biomass weight from 3 to 11 g, this peak shifts from 415 to 428 nm.…”

Metal Nanoparticles: Thermal Decomposition, Biomedicinal Applications to Cancer Treatment, and Future Perspectives

“…Wostek-Wojciechowska et al, Dallas et al, and Jung et al stated that thermal decomposition could be performed as either thermolysis or pyrolysis [ 33 – 35 ]. Dallas et al did the pyrolysis of his silver nanoparticles at a temperature of 300°C [ 34 ]. They also carried out thermolysis in both solid and liquid states [ 34 ].…”

“…Dallas et al did the pyrolysis of his silver nanoparticles at a temperature of 300°C [ 34 ]. They also carried out thermolysis in both solid and liquid states [ 34 ]. In the case of Wostek-Wojciechowska et al, they reported that better nanoparticles were obtained when in solution than in the solid state [ 33 ].…”

“…In order to measure the level of thermal stabilities of thermolysed nanoparticles, thermogravimetric analysis is needed. Dallas et al and Khalil et al observed the temperature of nanoparticles with thermogravimetric analysis (TGA) and differential thermal analysis (DTA) [ 34 , 36 ]. All the aforementioned authors reported temperatures below 300°C for the thermogravimetric analysis.…”